Air mover with thermally coupled guide vanes

ABSTRACT

An air mover comprising a housing and a plurality of blades rotatably disposed within the housing. A plurality of guide vanes are fixed within the housing. The guide vanes are thermally coupled to an electronic component such that heat generated by the electronic component is transferred through the guide vanes into an airflow generated by rotating the blades.

BACKGROUND

Computer systems include numerous electrical components that drawelectrical current to perform their intended functions. For example, acomputer's microprocessor or central processing unit (“CPU”) requireselectrical current to perform many functions such as controlling theoverall operations of the computer system and performing variousnumerical calculations. Generally, any electrical device through whichelectrical current flows produces heat. The amount of heat any onedevice generates generally is a function of the amount of currentflowing through the device.

Typically, an electrical device is designed to operate correctly withina predetermined temperature range. If the temperature exceeds thepredetermined range (i.e., the device becomes too hot or too cold), thedevice may not function correctly, thereby potentially degrading theoverall performance of the computer system. Thus, many computer systemsinclude cooling systems to regulate the temperature of their electricalcomponents. One type of cooling system is a forced air system thatrelies on one or more air movers to blow air over the electroniccomponents in order to cool the components.

In many applications, the air movers are positioned near the front orrear of a server chassis and either push or pull air through thechassis. Although effective, as the amount of heat generated by theelectronic devices increases the volume of air that is needed forcooling increases. In certain applications, such as high densityservers, there is limited free space within the chassis for large fansor for the flow of large volumes of air. Therefore, cooling systems forthese applications need to be compact and capable of generating highrates of flow.

BRIEF SUMMARY

The problems noted above are solved in large part by an air movercomprising a housing and a plurality of blades rotatably disposed withinthe housing. A plurality of guide vanes are fixed within the housing.The guide vanes are thermally coupled to an electronic component suchthat heat generated by the electronic component is transferred throughthe guide vanes into an airflow generated by rotating the blades.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of exemplary embodiments of the invention,reference will now be made to the accompanying drawings in which:

FIG. 1 shows a partial section view of an air mover constructed inaccordance with embodiments of the invention;

FIG. 2 shows a cross-sectional view of an air mover constructed inaccordance with embodiments of the invention;

FIG. 3 shows a cross-sectional view of a heat source coupled to an airmover constructed in accordance with embodiments of the invention;

FIG. 4 shows a cross-sectional view of heat transfer elements integratedinto an air mover constructed in accordance with embodiments of theinvention;

FIG. 5 shows a cross-sectional view of a heat source directly coupled toan air mover constructed in accordance with embodiments of theinvention;

FIG. 6 shows a cross-sectional view of heat source directly coupled toheat transfer elements integrated into an air mover constructed inaccordance with embodiments of the invention;

FIG. 7 shows a cross-sectional view of the air mover of FIG. 6;

FIGS. 8 and 9 show a cross-sectional view of a two-part air moverconstructed in accordance with embodiments of the invention;

FIG. 10 shows a cross-sectional view of a heat sink coupled to an airmover constructed in accordance with embodiments of the invention; and

FIG. 11 shows an end view of the heat sink of FIG. 10.

NOTATION AND NOMENCLATURE

Certain terms are used throughout the following description and claimsto refer to particular system components. As one skilled in the art willappreciate, computer companies may refer to a component by differentnames. This document does not intend to distinguish between componentsthat differ in name but not function. In the following discussion and inthe claims, the terms “including” and “comprising” are used in anopen-ended fashion, and thus should be interpreted to mean “including,but not limited to . . . .” Also, the term “couple” or “couples” isintended to mean either an indirect or direct connection. Thus, if afirst device couples to a second device, that connection may be througha direct connection, or through an indirect connection via other devicesand connections.

DETAILED DESCRIPTION

The following discussion is directed to various embodiments of theinvention. Although one or more of these embodiments may be preferred,the embodiments disclosed should not be interpreted, or otherwise used,as limiting the scope of the disclosure, including the claims. Inaddition, one skilled in the art will understand that the followingdescription has broad application, and the discussion of any embodimentis meant only to be exemplary of that embodiment, and not intended tointimate that the scope of the disclosure, including the claims, islimited to that embodiment.

Referring now to FIG. 1, air mover 10 comprises cylindrical housing 12surrounding rotating blades 14, stationary guide vanes 16, and motor 18.Motor 18 rotates blades 14 to draw air from inlet 13. The airflowgenerated by rotating blades 14 is straightened as it moves overstationary guide vanes 16 and travels through exhaust 15 as a primarilyaxial airflow. Stationary guide vanes 16 reduce disturbances in theairflow as it leaves rotating blades 14. This reduction in disturbancesresults in higher pressures, increased efficiency, and lower noiselevels.

Referring now to FIG. 2, a cross-sectional view of an air mover 20comprising cylindrical housing 22 surrounding rotating blades 24,stationary guide vanes 26, and motor 28. Stationary guide vanes 26 areconstructed from a heat-conductive material so as to act as a heat sinkwhen thermally coupled to a heat source. Stationary guide vanes 26 maybe constructed from a highly conductive metal, such as copper, or fromsome other highly conductive material.

As the highly turbulent airflow generated by rotating blades 24 passesover stationary guide vanes 26, heat is transferred between thestationary guide vanes and the airflow. The amount of heat that can betransferred into the airflow is dependent on properties of the air andthe velocity of the airflow. The highly turbulent airflow that passesover stationary guide vanes 26 has a high heat transfer coefficient.Therefore, the airflow can effectively remove large amounts of heat fromstationary guide vanes 26. Air mover 20 may comprise a large number ofstationary guide vanes 26 having a considerable surface area. In someapplications, the heat transfer provided by stationary guide vanes 26may be used to supplement or eliminate other heat transfer components.

In order to improve performance, the stationary guide vanes of the airmover are thermally coupled to a heat source, such as an electronicdevice. For example, FIG. 3 illustrates an air mover 30 comprisingstationary guide vanes 32 constructed from a heat-conductive material.Air mover 30 also comprises one or more heat pipes 34 that thermallycouple stationary guide vanes 32 to a heat-generating electroniccomponent 36. Heat produced by electronic component 36 is transferredthrough heat pipes 34 to the portion of air mover 30 comprisingstationary guide vanes 32. Heat pipes 34 may circumferentially surroundthe outer surface of air mover 30. Multiple heat pipes 34 may thermallycouple air mover 30 to a plurality of electronic components 36, andother heat sources, located throughout an electronic system.

In certain embodiments, the portion of an air mover containing thestationary guide vanes, known as a stator section, may be a moldedcomponent including heat transfer elements, such as heat pipes or acoolant loop. The heat transfer elements can be positioned and thestator section molded over them. The mold compound may be a materialwith a high thermal conductivity, such as a graphite, or carbon fiber,filled plastic molding compound, or a powder metallurgy metallicmaterial. By molding the stator section directly onto heat transferelements, a very good thermally conductive path to the stationary guidevanes can be achieved. In other embodiments, a metal sleeve may beplaced directly over housing. A highly conductive grease or othermaterial may enhance the heat transfer between the housing and anexternal sleeve. FIG. 4 illustrates an air mover 40 comprisingstationary guide vanes 42 constructed from a heat-conductive material.Air mover 40 also comprises integrated heat transfer elements 44 thatthermally couple stationary guide vanes 42 to one or moreheat-generating electronic components 46.

In some embodiments, a heat-conductive air mover may be directly coupledto an electronic component. FIG. 5 illustrates an air mover 50comprising stationary guide vanes 52 constructed from a heat-conductivematerial. Air mover 50 is directly coupled to a heat-generatingelectronic component 54. Heat generated by electronic component 54 isdirectly transferred into air mover 50 and dissipated to the airflowthrough stationary guide vanes 52 as the highly turbulent airflow passesover the stationary guide vanes. In certain embodiments, stationaryguide vanes 52 may comprise sufficient surface area to provide all ofthe cooling needed for the electronic component. A highly conductivegrease, or other material, may be disposed between and enhance the heattransfer between air mover 50 and electronic component 54.

To more evenly distribute the heat generated by a directly-coupledelectronic component, an air mover may further comprise integral heattransfer elements to distribute the heat around the air mover. FIGS. 6and 7 illustrate an air mover 60 comprising stationary guide vanes 62constructed from a heat-conductive material. Air mover 60 is directlycoupled to a heat-generating electronic component 64. Heat transferelements 66 are provided to further increase overall heat transfer bydistributing heat from electronic component 64 circumferentially aroundstationary guide vanes 62. Heat transfer elements 66 may be heat pipes,liquid-filled loops, or other heat transfer systems.

In selected applications, it may be desirable to be able to remove andmaintain certain components of an air mover without interrupting thethermal coupling between an electronic component and the air mover. Thecomponents of an air mover that require the most routine maintenance arethe moving parts, namely the rotating blades and the motor. FIGS. 8 and9 show an air mover 80 comprising a removable rotor housing 82 and afixed stator housing 84. Rotor housing 82 comprises intake housing 86,rotating blades 88, and motor 90. Stator housing 84 comprises exhausthousing 92, stationary guide vanes 94, and receptacle 96. Receptacle 96is operable to receive motor 90 and provide for alignment between therotor housing 82 and stator housing 84. Quick disconnect electrical andmechanical connectors provide attachment between rotor housing 82 andstator housing 84 while allowing easy removal and replacement of rotorhousing 82. In certain embodiments, stator housing 84 may comprise adamper assembly to prevent reverse flow when rotor housing 82 isremoved.

In some applications, the heat transfer capacity of the stationary finsmay not be sufficient for all of the cooling needs of a system. In theseapplications, the airflow into or out of the air mover can be furtherutilized as a heat transfer medium. FIGS. 10 and 11 show an air mover100 comprising an external, radial heat sink 110. Air mover 100comprises cylindrical housing 102 surrounding rotating blades 104,stationary guide vanes 106, and motor 108. Radial heat sink 110comprises center portion 112 and radial fins 114. Radial heat sink 110is disposed adjacent to the exhaust end of housing 102. A heat pipe orliquid cooling radiator tube may be disposed within center portion 112.

Heat enters center portion 112 through the heat pipe or liquid coolingsystem that is thermally coupled to a heat source, such as amicroprocessor or other electronic device. Heat is rejected from fins114 into the air moving through air mover 100. Heat sink 110 can beplaced at either the inlet or exhaust of an air mover. In certainembodiments, heat sink 110 can be combined with ductwork that improvesthe flow of air over the radial-finned heat sink. In other embodiments,heat may be transferred to fins 114 from their outer diameter inaddition to, or alternatively to, heat from center portion 112.

The above discussion is meant to be illustrative of the principles andvarious embodiments of the present invention. Numerous variations andmodifications will become apparent to those skilled in the art once theabove disclosure is fully appreciated. For example, air movers ofdifferent sizes, shapes, and configurations may utilize the principlesof the present invention. It is intended that the following claims beinterpreted to embrace all such variations and modifications.

1. An air mover comprising: a housing; a plurality of blades rotatablydisposed within said housing; and a plurality of guide vanes fixedwithin said housing, wherein said guide vanes are thermally coupled toan electronic component such that heat generated by the electroniccomponent is transferred through said guide vanes into an airflowgenerated by rotating said plurality of blades.
 2. The air mover ofclaim 1 further comprising a heat transfer element that thermallycouples said guide vanes to the electronic component.
 3. The air moverof claim 2 wherein said heat transfer element comprises a heat pipe. 4.The air mover of claim 2 wherein said heat transfer element comprises afluid loop.
 5. The air mover of claim 2 wherein said heat transferelement is integrated into said housing proximate to said plurality ofguide vanes.
 6. The air mover of claim 1 wherein said housing isdirectly coupled to the electronic component.
 7. The air mover of claim1 further comprising a heat sink coupled to said housing.
 8. The airmover of claim 7 wherein said heat sink comprises a plurality of finsprotruding radially from a center portion.
 9. The air mover of claim 1wherein said plurality of blades are removable from said plurality ofguide vanes.
 10. A computer assembly comprising: a electronic componentthat generates heat; an air mover comprising a stator housing and arotor housing, wherein the stator housing is thermally coupled to saidelectronic component; a plurality of rotating blades disposed within therotor housing; a motor coupled to said plurality of rotating blades,wherein said motor is disposed within the rotor housing; a plurality ofstationary guide vanes disposed within the stator housing such that anairflow generated by said rotating blades passes across said guidevanes.
 11. The computer assembly of claim 10 wherein the rotor housingof said air mover is detachable from the stator housing of said airmover.
 12. The computer assembly of claim 10 further comprising a heattransfer element that thermally couples the stator housing of said airmover to said electronic component.
 13. The computer assembly of claim10 wherein the stator housing of said air mover is directly coupled tosaid electronic component.
 14. The computer assembly of claim 10 whereinthe stator housing of said air mover further comprises integral heattransfer elements.
 15. The computer assembly of claim 14 wherein saidheat transfer elements comprise a fluid loop.
 16. The computer assemblyof claim 14 wherein said heat transfer elements comprise a heat pipe.17. A heat transfer method comprising: thermally coupling a plurality ofstationary guide vanes to a heat generating component; rotating aplurality of blades so as to generate an airflow; and passing theairflow across the plurality of stationary guide vanes so as tostraighten the airflow and transfer heat from the stationary guide vanesinto the airflow.
 18. The heat transfer method of claim 17 wherein thestationary guide vanes are thermally coupled to the heat generatingcomponent by a heat pipe.
 19. The heat transfer method of claim 17further comprising passing the airflow over a heat sink comprising aplurality of fins protruding radially from a center portion that isthermally coupled to a heat source.
 20. The heat transfer method ofclaim 17 wherein the plurality of stationary guide vanes are disposedwithin a housing that is directly coupled to the heat generatingcomponent.